Inuyasha has a happy ending but my question is this since she went back and time and became a shrine maiden for the very shrine her family looks after does that make her her own great great great great great great great grandmother O.o time travel is always so confusing xD

well, in clannad
http://www.mangahere.com/manga/clannad/
they get married in the second season, but its not exactly a happy ending. (sorry, that was meant as a warning, not a spoiler.)
also, ouran high school host club is really funny and cute, there's an anime and a manga but they don't even get as far as a proper confession in the anime, let alone marriage. in the manga, if you read the extra special chapters you hear other characters talking about how they got married and how she's pregnant and stuff, but i don't know if you actually see the wedding since i haven't read that far yet but it's still really cute and yeah, basically its a given that they get married whether you see it or not.